Systems and methods for calibrating conversion models and performing position conversions of variable capacitors in match networks of plasma processing systems

ABSTRACT

A control system is provided and includes a memory and a conversion module. The memory is configured to store position data of first positions of a first variable capacitor of a first match network of a first plasma processing system. Each of the first positions of the first variable capacitor corresponds to a respective one of multiple loads experienced by the first match network. The conversion module is configured to: obtain the position data stored in the memory; determine reference capacitor positions based on the position data; determine a calibrated conversion model based on the reference capacitor positions, where the calibrated conversion model converts second positions of the first variable capacitor to comparable capacitor positions, and where the second positions are positions of the first variable capacitor existing subsequent to the determination of the calibrated conversion model; and store the calibrated conversion model.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/250,648 filed Nov. 4, 2015. The entire disclosure of the applicationreferenced above is incorporated herein by reference.

FIELD

The present disclosure relates to etching and deposition systems, andmore particularly, to transformer coupled capacitive tuning systems.

BACKGROUND

The background description provided here is for the purpose of generallypresenting the context of the disclosure. Work of the presently namedinventors, to the extent it is described in this background section, aswell as aspects of the description that may not otherwise qualify asprior art at the time of filing, are neither expressly nor impliedlyadmitted as prior art against the present disclosure.

During manufacturing of semiconductor devices, etch processes anddeposition processes may be performed within a processing chamber.Ionized gas, or plasma, can be introduced into the plasma chamber toetch (or remove) material from a substrate such as a semiconductorwafer, and to sputter or deposit material onto the substrate. Creatingplasma for use in manufacturing or fabrication processes typicallybegins by introducing process gases into the processing chamber. Thesubstrate is disposed in the processing chamber on a substrate supportsuch as an electrostatic chuck or a pedestal.

The processing chamber may include transformer coupled plasma (TCP)reactor coils. A radio frequency (RF) signal, generated by a powersource, is supplied to the TCP reactor coils. A dielectric window,constructed of a material such as ceramic, is incorporated into an uppersurface of the processing chamber. The dielectric window allows the RFsignal to be transmitted from the TCP reactor coils into the interior ofthe processing chamber. The RF signal excites gas molecules within theprocessing chamber to generate inductively-coupled plasma.

The TCP reactor coils are driven by a transformer coupled capacitivetuning (TCCT) match network. The TCCT match network receives the RFsignal supplied by the power source and enables tuning of power providedto the TCP reactor coils. The TCCT match network may include variablecapacitors. Each of the variable capacitors includes a stationaryelectrode and a movable electrode. A capacitance of the correspondingcapacitor is directly related to position of the movable electroderelative to the stationary electrode. The movable electrodes can beconnected to a leadscrew, which can be driven by a rotary motor.

Power supplied to each of the TCP reactor coils is based on positions ofthe movable electrodes of the capacitors. A ratio of power delivered tothe TCP coils is also based on the positions of the movable electrodesof the capacitors. One or more power ratios provided during etching canbe different than one or more power ratios provided during deposition.

SUMMARY

A control system is provided and includes a memory and a conversionmodule. The memory is configured to store position data of firstpositions of a first variable capacitor of a first match network of afirst plasma processing system. Each of the first positions of the firstvariable capacitor corresponds to a respective one of multiple loadsexperienced by the first match network. The conversion module isconfigured to: obtain the position data stored in the memory; determinereference capacitor positions based on the position data; determine acalibrated conversion model based on the reference capacitor positions,where the calibrated conversion model converts second positions of thefirst variable capacitor to comparable capacitor positions, and wherethe second positions are positions of the first variable capacitorexisting subsequent to the determination of the calibrated conversionmodel; and store the calibrated conversion model.

In other features, a control system is provided and includes a memoryand a conversion module. The memory is configured to store position dataof first positions of a variable capacitor of a first power splitter ofa first plasma processing system. Each of the first positions of thevariable capacitor corresponds to a respective one of multiple loadsexperienced by the first power splitter. The conversion module isconfigured to: obtain the position data stored in the memory; determinereference capacitor positions based on the position data; determine acalibrated conversion model based on the reference capacitor positions,where the calibrated conversion model converts second positions of thevariable capacitor to comparable capacitor positions, and where thesecond positions are positions of the variable capacitor existingsubsequent to the determination of the calibrated conversion model; andstore the calibrated conversion model.

Further areas of applicability of the present disclosure will becomeapparent from the detailed description, the claims and the drawings. Thedetailed description and specific examples are intended for purposes ofillustration only and are not intended to limit the scope of thedisclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIG. 1 is a functional block diagram of an example of a plasmaprocessing system incorporating a position conversion controller inaccordance with the present disclosure;

FIG. 2 is a schematic view of an example of a TCCT match network and acorresponding capacitance adjustment system in accordance with thepresent disclosure;

FIG. 3 is a functional block diagram of another example of a TCCT matchnetwork;

FIG. 4 is a schematic diagram of an example of the TCCT match network ofFIG. 3 in accordance with the present disclosure;

FIG. 5 is a schematic diagram of an example of a RF match network of abias match network;

FIG. 6 is a functional block diagram of an example of a control systemincorporating the position conversion controller in accordance with anembodiment of the present disclosure;

FIG. 7 illustrates a calibration method in accordance with an embodimentof the present disclosure;

FIG. 8A is an example plot of a comparable capacitor position curve anda quartic polynomial conversion curve for detected capacitor positionsin accordance with an embodiment of the present disclosure;

FIG. 8B is an example plot of error between the comparable capacitorposition curve and the quartic polynomial conversion curve of FIG. 8A;

FIG. 9A is an example plot of a comparable capacitor position curve anda quadratic polynomial conversion curve for detected capacitor positionsin accordance with an embodiment of the present disclosure;

FIG. 9B is an example plot of error between the comparable capacitorposition curve and the quadratic polynomial conversion curve of FIG. 9A;

FIG. 10A is an example plot of a comparable capacitor position curve anda linear conversion curve for detected capacitor positions in accordancewith an embodiment of the present disclosure;

FIG. 10B is an example plot of error between the comparable capacitorposition curve and the linear conversion curve of FIG. 10A; and

FIG. 11 illustrates a method of operating the control system of FIG. 6and the plasma processing system of FIG. 1 in accordance with anembodiment of the present disclosure.

In the drawings, reference numbers may be reused to identify similarand/or identical elements.

DETAILED DESCRIPTION

A traditional TCCT match network may include a radio frequency (RF)match network and a power splitter, which may include variablecapacitors (e.g., vacuum variable capacitors). The variable capacitorsof the power splitter correspond to TCP reactor coils of a processingchamber. Each of the variable capacitors may include stationaryelectrodes and movable electrodes. The TCP reactor coils may include aninner coil and an outer coil. The inner coil is disposed within an outercoil. A ratio of power supplied to the inner coil relative to powersupplied to the outer coil is adjusted by moving the moveable electrodesof the capacitors relative to the stationary electrodes. The moveableelectrodes may be moved via respective leadscrews and rotary motors.

A processing facility of a customer may have multiple processingchambers. Each processing chamber may have a respective TCCT matchnetwork. Manufacturing differences associated with components of RFmatch networks and power splitters in the TCCT match networks andmanufacturing variations in the processing chambers can result indifferent capacitor positions and loads on the TCCT match networks. Asan example, manufacturing differences of the capacitors may result inthe same corresponding capacitors of different TCCT match networkshaving difference capacitances for a same position. Also, positions ofthe variable capacitors of the TCCT match networks can be adjusted to,for example, maximize power transfer through the RF match networks,minimize reflected power, and provide predetermined power ratios. As aresult, set positions of the variable capacitors of the TCCT matchnetworks of the same type can be different when operating according to asame recipe.

Differences in positions of the same corresponding capacitors ofdifferent TCCT match networks may be used by a customer as an indicatorof an issue with one of the processing chambers and/or one of the TCCTmatch networks (referred to as an “outlier chamber” or an “outlier TCCTmatch network”). To determine if an issue exists, capacitor positions ofthe TCCT match networks may be compared for operation of the processingchambers according to a same recipe. If, for example, a position of acapacitor of a first RF match network for a first processing chamber isnot the same or within a predetermined range of the positions of thesame corresponding capacitors in the RF match networks of the otherprocessing chambers, then an issue may exist with the first RF matchnetwork. The difference in positions may be used as an early indicatorto predict that the first RF match network has degraded and/or needs tobe fixed or replaced. As an example, a component of the first RF matchnetwork may have degraded, such that the first RF match network is morelossy than the other RF match networks. However, due to themanufacturing differences of the TCCT match networks and/or theprocessing chambers, differences in capacitor positions can provide afalse alarm. An incorrect determination may be made that the first RFmatch network or a corresponding power splitter needs to be fixed orreplaced. For example, the position of the capacitor of the first RFmatch network may be different due to the stated manufacturingdifferences and not due to component degradation. This difference may belarge enough to cause a false alarm. False alarms can cause frequentremoval and/or replacement of RF match networks, power splitters, andTCCT match networks.

A RF match network may include two or more inductor-capacitor branches,where each branch includes an inductor connected series with acapacitor. Each branch is characterized by three parameters; aninductance of the inductor, a capacitance of the capacitor, and acapacitance per count ratio α. Positions of the capacitors may bereferred to as a number of counts, where zero counts refers to a minimumcapacitance position and a maximum amount of counts (e.g., 1000 counts)refers to a maximum capacitance position. For example, a capacitanceC(s) of a variable vacuum capacitor may be represented by equation 1,where C₀ is a base capacitance and s refers to the position of thevariable vacuum capacitor.

C(s)=C ₀ +αs  (1)

The base capacitance may refer to a low end capacitance (e.g., a minimumcapacitance or 0 pico-farads (pF)) or a high end capacitance (e.g., amaximum capacitance or 1500 pF). Variation in any of the threeparameters of each of the branches causes the capacitor position s to bedifferent from RF match network to RF match network, although theimpedances of the same corresponding branch of the RF match networks arethe same. As a result, false alarms can regularly occur because of thevariations in the three parameters.

The examples set forth below include performing capacitor positionconversions to minimize and prevent false alarms from occurring. Thecapacitor position conversions include converting actual capacitorpositions for which corresponding comparisons may not be reliable, tocomparable capacitor positions (referred to herein as “golden matchpositions”) that minimize and/or prevent generation of false alarms. Theconversion in effect minimizes and/or removes the variability inreported capacitor positions due to manufacturing differences. Thereference and/or average capacitor positions are generated and mappedfrom corresponding actual capacitor positions to provide a calibratedconversion model. A calibrated conversion model may be generated duringa calibration process of each variable capacitor of a match network. Acalibrated conversion model is then used to convert the actual capacitorpositions to comparable capacitor positions, which may then be used toevaluate performance of the match network.

FIG. 1 shows a plasma processing system 10 that includes a RF powerratio switching system 11, a plasma processing chamber 12, and TCPreactor coils 14. The RF power ratio switching system 10 switches RFpower ratios of the TCP reactor coils 14. The TCP reactor coils 14 aredisposed outside and above the plasma processing chamber 12. A firstpower source 16 provides a first RF source signal. The RF power ratioswitching system 11 includes a TCCT (or first) match network 17. TheTCCT match network 17 is included between the first power source 16 andthe TCP reactor coils 14. The TCCT match network 17 enables tuning ofpower provided to the TCP reactor coils 14. The TCCT match network 17includes a TCCT capacitance adjustment system 18, which includes a TCCTcontroller 19 that controls adjustment of positions and/or capacitancesof variable capacitors included in the TCCT match network 17.

The plasma processing chamber 12 includes a dielectric window 20, whichis located adjacent the TCP reactor coils 14 and allows efficienttransmission of the first RF source signal into the plasma processingchamber 12 for plasma generation purposes. A substrate support 21 suchas an electrostatic chuck, a pedestal or other suitable substratesupport is disposed at the bottom of the plasma processing chamber 12.The substrate support 21 supports a substrate 22. If the substratesupport 21 is an electrostatic chuck, the substrate support 21 includeselectrically conductive portions 24 and 26, which are electricallyisolated from each other. The substrate support 21 is surrounded by aninsulator 28 and is capacitively coupled to the substrate 22. Byapplying a DC voltage across the conductive portions 24, 26, anelectrostatic coupling is created between the conductive portions 24, 26and the substrate 22. This electrostatic coupling attracts the substrate22 against the substrate support 21.

The plasma processing system 10 further includes a bias RF power source30, which is connected to a bias (or second) match network 32. The biasmatch network 32 is connected between the bias RF power source 30 andthe substrate support 21. The bias match network 32 matches an impedance(e.g., 50Ω) of the bias RF power source 30 to an impedance of thesubstrate support 21 and plasma 35 in the plasma processing chamber 12as seen by the bias matching network 32. The bias match network 32includes a bias capacitance adjustment system 33, which includes a biascontroller 34. The bias controller 34 controls adjustment of positionsand/or capacitances of variable capacitors included in the bias matchnetwork 32.

The capacitance adjustment systems 18, 33 may include actuators, such asmotors, which are controlled by the controllers 19, 34. The actuatorsmay be connected to shafts of the variable capacitors. The controllers19, 34 adjust positions of the variable capacitors included in the TCCTmatch network 17 and in the bias match network 32 to adjust capacitancesof the variable capacitors. The position adjustments of the variablecapacitors in match networks 17, 32 adjust impedances of RF matchnetworks included in the networks 17, 32. The position adjustments ofthe variable capacitors in the TCCT match network 17 adjust a RF powerratio of power supplied to the TCP reactor coils 14. Examples of thevariable capacitors, the RF match networks, and other circuitry of thematch networks 17, 32 are shown in FIGS. 3-5. Although the capacitanceadjustment systems 18, 33 are shown as part of the match networks 17,32, portions or all of the capacitance adjustment systems 18, 33 may beseparate from the match networks 17, 32. The match networks 17, 32 maybe implemented as stand-alone circuits and/or systems having respectivehousings with inputs and outputs.

The plasma processing system 10 further includes a voltage controlinterface (VCI) 40. The VCI 40 may include a pickup device 42, a voltagesensor 44, a system controller 46 and circuits between the voltagesensor 44 and the system controller 46. The pickup device 42 extendsinto the substrate support 21. This pickup device 42 is connected via aconductor 48 to the voltage sensor 44 and is used to generate a RFvoltage signal.

Operation of the voltage sensor 44 may be monitored, manuallycontrolled, and/or controlled via the system controller 46. The systemcontroller 46 may display output voltages of the channels of the voltagesensor 44 on a display 50. Although shown separate from the systemcontroller 46, the display 50 may be included in the system controller46. A system operator may provide input signals via an input device 52indicating (i) whether to switch between the channels, (ii) which one ormore of the channels to activate, and/or (ii) which one or more of thechannels to deactivate.

The system controller 46 includes a position conversion controller 54that performs capacitor position conversions. This includes convertingactual positions of the variable capacitors of the match networks 17, 32to golden match positions. The golden match positions are then displayedon the display 50. The conversion process is further described belowwith respect to FIGS. 6-11. The system controller 46 may also comparepositions of the same corresponding variable capacitors of multiple TCCTmatch networks and/or bias match networks of multiple processing systemsand/or chambers. The system controller 46 may indicate via the display50 the comparison results. The system controller 46 may also indicate,based on the comparison results, whether an issue exists with one of thematch networks 17, 32 and/or RF impedance match networks and/or powersplitters included in the match networks 17, 32.

In operation, a gas capable of ionization flows into the plasmaprocessing chamber 12 through the gas inlet 56 and exits the plasmaprocessing chamber 12 through the gas outlet 58. The first RF signal isgenerated by the RF power source 16 and is delivered to the TCP reactorcoil 14. The first RF signal radiates from the TCP reactor coil 14through the window 20 and into the plasma processing chamber 12. Thiscauses the gas within the plasma processing chamber 12 to ionize andform the plasma 35. The plasma 35 produces a sheath 60 along walls ofthe plasma processing chamber 12. The plasma 35 includes electrons andpositively charged ions. The electrons, being much lighter than thepositively charged ions, tend to migrate more readily, generating DCbias voltages and DC sheath potentials at inner surfaces of the plasmaprocessing chamber 12. An average DC bias voltage and a DC sheathpotential at the substrate 22 affects the energy with which thepositively charged ions strike the substrate 22. This energy affectsprocessing characteristics such as rates at which etching or depositionoccurs.

The system controller 46 may adjust the bias RF signal generated by theRF power source 30 to change the amount of DC bias and/or a DC sheathpotential at the substrate 22. The system controller 46 may compareoutputs of the channels of the voltage sensor 44 and/or a representativevalue derived based on the outputs of the channels to one or more setpoint values. The set point values may be predetermined and stored in amemory 62 of the system controller 46. The bias RF signal may beadjusted based on differences between (i) the outputs of the voltagesensor 44 and/or the representative value and (ii) the one more setpoint values. The bias RF signal passes through the bias match network32. An output provided by the bias match network 32 (referred to as amatched signal) is then passed to the substrate support 21. The bias RFsignal is passed to the substrate 22 through the insulator 28.

FIG. 2 shows an example of the TCCT match network 17 connected toexamples TCP reactor coils 100, 102, 104, 106. The TCP reactor coils100, 102 are collectively referred to as an outer coil. The TCP reactorcoils 104, 106 are collectively referred to as an inner coil. The outercoil and inner coil may be spiral-shaped as shown or may have adifferent shape and/or configuration. The TCCT match network 17 includesTCCT coil input circuits 110 and TCCT coil output circuits 112. The TCCTcoil input circuits 110 are connected to the inner coil at coil ends Dand E and to the outer coil at coil ends B and G. The TCCT coil outputcircuits 112 are connected to the inner coil at coil ends C and F and tothe outer coil at coil ends A and H. The TCCT coil input circuits 110receive power from the power source 16, which is connected to areference terminal (or ground reference) 120. The TCCT coil outputcircuits 112 are connected to the reference terminal 120.

The TCCT coil input circuits 110 include variable capacitors; examplesof which are shown in FIGS. 3-5. Position adjustment of the variablecapacitors adjusts power supplied from the TCCT coil input circuits 110to the inner coil and the outer coil, respectively. This adjusts a RFpower ratio between the inner coil and the outer coil. The TCCTcapacitance adjustment system 18 is connected to the TCCT coil inputcircuits 110 and is controlled by the TCCT controller 19, which isconnected to the system controller 46.

The TCCT capacitance adjustment system 18 may include registers 114 forstoring positions of the variable capacitors of the TCCT match network17. This may include storing actual (or raw) positions of the variablecapacitors and/or storing reference capacitor positions, which may bereceived from the system controller 46 and/or the position conversioncontroller 54.

FIG. 3 shows a TCCT match network 150 that may replace the TCCT matchnetwork 17 of FIGS. 1-2. The TCCT match network 150 receives power fromthe power source 16. The TCCT match network 150 includes a RF matchnetwork 152, an inner coil input circuit 154, an outer coil inputcircuit 156, an inner coil output circuit 158, and an outer coil outputcircuit 160. The coil input circuits 154, 156 may include a firstvariable capacitor 162 and a second variable capacitor 164 and providepower to an inner coil IC 166 and an outer coil OC 168. Power out of thecoils 166, 168 is provided to the coil output circuits 158, 160, whichare connected to the reference terminal 120. The variable capacitors162, 164 are adjusted by the TCCT controller 19 via, for examples,actuators of the TCCT capacitance adjustment system.

FIG. 4 shows a TCCT match network 200, which is an example of the TCCTmatch network 150 of FIG. 3. The TCCT match network 200 receives powerfrom the power source 16. The TCCT match network 200 includes the RFmatch network 152, an inner coil input circuit 202, an outer coil inputcircuit 204, the inner coil output circuit 206, and the outer coiloutput circuit 208. The RF match network 152 may include three branchesin a ‘T’-type network configuration. The first branch includes a firstcapacitor C1 and a first inductor L1. The second branch includes asecond capacitor C2 and a second inductor L2. The third branch includesa third capacitor C3 and a third inductor L3. As an example, thecapacitors C1 and C3 may be variable capacitors and the inductors L1 andL2 may be parasitic inductances. The capacitors C1, C3 and inductors L1,L3 are connected in series between the power source 16 and the coilinput circuits 202, 204. The capacitor C2 and inductor L2 are connectedin series and between (i) an output of the capacitor C1 and an input ofthe capacitor C3, and (ii) the reference terminal 120.

The inner coil input circuit 202 may include capacitors C4, C5, wherecapacitor C5 is a variable capacitor. The capacitors C4 and C5 areconnected in series between the inductor L3 and an inner coil L4. Theinner coil output circuit 206 may include an inductor L5 that isconnected between the inner coil L4 and the reference terminal 120. Theouter coil input circuit 204 may include a capacitor C6 and an inductorL6 that are connected in series between the inductor L3 and an outercoil L7. The outer coil output circuit 208 may include a capacitor C7that is connected between the outer coil L7 and the reference terminal120.

The capacitors C1, C3, C5, C6 may be variable capacitors, which areadjusted by the capacitance adjustment system 19. The capacitiveadjustment system 19 may receive signals from sensors 210 (e.g.,potentiometers, encoders, etc.) for detecting positions of one or moreshafts and/or rods of actuators 212 and the capacitors C1, C3, C5, C6.The sensors 210 may be included in the actuators 212, on the actuators212, and/or connected directly and/or indirectly to the shafts and/orrods. The controller 46 of FIG. 1 may adjust voltage, current and/orpower supplied to the actuators 212 to adjust position of the shaftsand/or rods based on signals received from the sensors 210.

FIG. 5 shows a RF match network 250 that may be implemented in the biasmatch network 32 of FIG. 1. The RF match network 250 is in a ‘L’-typeconfiguration and includes two branches. The first branch includes acapacitor C1 and inductor L1. The second branch includes capacitor C2and inductor L2. The first inductor L1 and the second capacitor C2receive RF_(IN) from, for example, the source 30 of FIG. 1 via an inputterminal 252. The capacitor C1 and the inductor L1 are connected inseries between the input terminal 252 and the reference terminal 120.The capacitor C2 and the inductor L2 are connected in series between theinput terminal 252 and an output terminal 254. The capacitors C1, C2 maybe variable capacitors adjusted by the bias capacitance adjustmentsystem 33 of FIG. 1. The bias match network 32 of FIG. 1 may includeactuators and sensors similar to the TCCT match network 17 for adjustingpositions of the capacitors C1, C2.

FIG. 6 shows a control system 300 incorporating the controllers 19, 34and the position conversion controller 54 of FIG. 1. Although shown asseparate controllers, the controllers 19, 34 and 54 may be implementedas a single controller and/or the controllers 19, 34 may be implementedas part of the controller 54. The TCCT controller 19 includes the TCCTregisters 114. The bias controller 34 may include bias registers 302.The bias registers may store actual positions of variable capacitors(e.g., capacitors C1, C2 of FIG. 5) of the bias match network 32 and/orreference capacitor positions provided by the system controller 46and/or the position conversion controller 54.

The position conversion controller 54 includes a first positioncollection module 310, a second position collection module 312, a memory314, a TCCT conversion module 316, a bias conversion module 318, adisplay module 320, a comparison module 322 and a degradation reportingmodule 324. The modules 310, 312 may communicate with the controllers19, 34 via a digital communication interface (e.g., a RS-232 interface,an Ethernet interface, an Ethernet for control automation technology(EtherCat) interface, or other suitable interface). The memory 314stores actual detected and/or commanded capacitor positions 330,position conversion models 332, reference capacitor positions 333, andcomparable capacitor (or golden match) positions 334. The memory 314 mayalso store results of (i) comparisons between capacitances and/orpositions of variable capacitors of TCCT match networks, and/or (ii)comparisons between capacitances and/or positions of variable capacitorsof bias match networks. The comparable capacitor positions 334, thecomparison results, and/or issues determined based on an evaluation ofthe comparison results may be shown on the display 50.

For further defined structure of the controllers and modules of FIGS.1-4 and 6 see below provided methods of FIGS. 7 and 11 and belowprovided definitions for the term “controller” and “module”. The systemsdisclosed herein may be operated using numerous methods, example methodsare illustrated in FIGS. 7 and 11. In FIG. 7, a calibration method forcalibrating the control system 300 is shown. Although the followingtasks are primary described with respect to the control system 300 beingcalibrated while being implemented and operated in the plasma processingsystem 10, the control system 300 may be calibrated (i) duringmanufacturing of the plasma processing system and/or a portion thereof,(ii) on a test stand, and/or (iii) in another plasma processing system10. The control system 300 may be implemented in the plasma processingsystem 10 subsequent to calibration. Although the following operationsare primarily described with respect to the implementations of FIGS.1-6, the operations may be easily modified to apply to otherimplementations of the present disclosure. The operations may beiteratively performed.

The method may begin at 400. Although operations 402-407 are shown,tasks 402-406 or operation 407 may not be performed. Operations 402-407are shown as examples operations for collecting variable capacitorposition data. During operations 402-406, the match networks 17, 32 areoperated based on a finite number of predetermined loads and for afinite number of recipes. The predetermined loads may (i) be test loadshaving impedances associated with recipes used during normal operation,or (ii) actual loads experienced under normal operating conditions.Although tasks 402-406 are described as being performed for matchnetworks 17, 32 and the plasma processing system 10, the tasks 402-406may also be performed for other match networks and plasma processingsystem of the same type as the match networks 17, 32 and the plasmaprocessing system 10 and operating based on the same predetermined loadsand recipes. The phrase “same type” refers to match networksmanufactured with the same components and configured the same to providesimilar results, such that one match network may be replace anothermatch network of the same type.

At 402, the match networks 17, 32 are operated while experiencing apredetermined load and a predetermined recipe for the plasma processingsystem 10. The system controller 46 may initiate and control operationof the controllers 19, 34, which control operation of the match networks17, 32. The load may be predetermined to provide stable consistentresults of variable capacitor positions. A recipe may refer to apredetermined gas mixture, a predetermined concentration level, apredetermined power level, predetermined bias voltages, etc.

At 403, the controllers 19, 34 may determine whether predeterminedrequirements have been satisfied, such as whether: predeterminedimpedances of the match networks 17, 32, 152 and/or the power splitter153 exist; a predetermined amount of power is being transferred throughthe match networks 17, 32, 152; and/or a predetermined power ratioexists between inner and outer coils (e.g., coils 100 and 102 of FIG. 2,coils 166 and 168 of FIG. 3, or coils L4 and L7 of FIG. 4). Thisdetermination may be based on signals from the sensors 44, 210 and/orother sensors included in the plasma processing system 10. If thepredetermined requirements are not satisfied, operation 404 isperformed, otherwise operation 405 is performed.

At 404, the controllers 19, 34 adjust the positions of the correspondingvariable capacitors, as described above. The adjusted positions of thevariable capacitors may be stored in the registers 114, 302. Operation403 may be performed subsequent to operation 404. At 405, the positioncollection modules 310, 312 may access the registers 114, 302 and storethe resultant positions of the variable capacitors in the memory 314.

At 406, the system controller 46 may determine whether to operate thematch networks 17, 32 based on another load condition and/or for anotherrecipe. Multiple load conditions may be provided for each recipe. Ifvariable capacitor positions are to be obtained for another loadcondition and/or another recipe, operation 402 may be performed,otherwise operation 408 may be performed. Completion of operations402-406 provides stored resultant capacitor position data for each loadand each recipe.

At 407, historical variable capacitor position data is collected andstored in the memory 314. This may include the position collectionmodules 310, 312 collecting capacitor position data from the registers114, 302 and/or from other registers of other match networks. The matchnetworks may correspond to processing chambers other than the plasmaprocessing chamber 12 and/or processing chambers of plasma processingsystems other than the plasma processing system 10. The historicalvariable capacitor position data may be for any number of matchnetworks, loads, recipes, and/or plasma processing chambers. Thehistorical variable capacitor position data may be for multiple versionsof the same type of match network connected to and/or supplying power toa same set of two or more loads. In one embodiment, operation 407 isperformed subsequent to tasks 402-406.

The calibration process may include collecting position data for eachvariable capacitor of a RF match network and/or a power splitter of aTCCT match network and/or of a bias match network. The capacitorposition data may be collected for one or more sets of match networkscorresponding to one or more plasma processing chambers. A set of matchnetworks may include, for example, the match networks of a particularplasma processing system and/or plasma processing chamber (e.g., thematch networks 17 and 32 of the plasma processing system 10 and/or theplasma processing chamber 12). The capacitor position data may becollected for each load of multiple predetermined loads experienced foreach of the plasma processing chambers. The capacitor position data maybe collected and grouped based on the type of the match network and/orbased on the corresponding plasma processing chamber of the matchnetwork.

At 408, the position conversion controller 54 may determine whethervariable capacitor position data is only available for one set of matchnetworks operating for one plasma processing chamber. When capacitorposition data is only available for a single set of match networksoperating for a single processing chamber, the set of match networks areoperated based on different loads during operations 402-406. Theresultant capacitor positions provided after being adjusted duringoperations 403-404 are stored at 405 and then used at 416. If data isonly available for one set of match networks, operation 409 isperformed, otherwise operation 410 is performed.

At 409, the conversion modules 316, 318 may set variable capacitorpositions as reference capacitor positions to be used as a reference foroperation 416. The conversion module 316 may perform operations forvariable capacitors of the TCCT match network 17. The conversion module318 may perform operations for variable capacitors of the bias matchnetwork 32. At 410, the modules 316, 318 may average capacitor positionsof the same corresponding capacitors of different match networks of thesame type, which correspond to different processing chambers operatingbased on a same load condition. For example, multiple RF match networksof different plasma processing chambers may include a version of thevariable capacitor C1 of FIG. 4. The RF match networks may be operatedbased on the same load and recipe and adjusted accordingly. Theresultant capacitor positions of the versions may be averaged to provideresultant average positions. This may be performed for each variablecapacitor of the same type and implemented in the same type of matchnetwork. At 412, the conversion modules 316, 318 set (i) the averagecapacitor positions to reference capacitor positions, or (ii) capacitorpositions associated with one of the match circuits and that are closestto the average capacitor positions as the reference capacitor positions.At 414, the modules 316, 318 store the reference capacitor positions inthe memory 314.

At 416, the modules 316, 318 determine calibrated conversion parameters,mapping relationships and/or a conversion model for each of the variablecapacitors of the match networks 17, 32. Calibrated conversionparameters may refer to unknowns of a conversion equation, unknowncoefficients of a conversion polynomial equation, and/or otherconversion parameters. Calibrated mapping relationships may refer torelationships between actual detected and/or commanded variablecapacitor positions and the reference capacitor positions. Calibratedconversion models may include a conversion equation, a conversionpolynomial equation, a linear equation, a conversion curve, a conversiontable, etc. Three examples are provided by operations 416A, 416B, 416C.

At 416A, the conversion modules 316, 318, for each variable capacitor,determine unknowns of a position conversion equation. The positionconversion equation may be a precise conversion from detected and/orcommanded variable capacitor positions to reference capacitor positionsbased on parameters of the corresponding circuit. An example conversionequation is shown for a RF match network as equation 2, where: s₂ is adetected and/or commanded capacitor position; s is a reference capacitorposition; C₀₂ is an actual capacitance of a capacitor of a branch of theRF match network; C₀ is capacitance corresponding to s; L2 is aninductance of a branch of the RF match network; L is an inductancecorresponding to s; α₂ is the capacitance per count ratio for thedetected capacitor position s; a is the capacitance per count ratio forthe reference capacitor position s₂; ΔL=L2−L; f{s₂} is the function ofs₂ to provide s as represented by equation 2, and ω is an angularfrequency of a RF signal through the RE match network. The values of C₀,L and a may be unknown and determined during operation 416A.Alternatively, values of P1-P4 may be unknown values that aredetermined, where, P1 is

$\frac{C_{0}}{\alpha},$

P2 is ω²ΔLC₀, P3 is

$\frac{C_{02}}{C_{0}},$

and P4 is

$\frac{\alpha_{2}}{\alpha}.$

$\begin{matrix}{s = {{f\left\{ s_{2} \right\}} = {{\frac{C_{0}}{\alpha}\left\{ \frac{1}{{\omega^{2}\Delta \; {LC}_{0}} + \frac{1}{\frac{C_{02}}{C_{0}} + {\frac{{\alpha\alpha}_{2}}{C_{0}\alpha}s_{2}}}} \right\}} = {P\; 1\left\{ {\frac{1}{{P\; 2} + \frac{1}{{P\; 3} + {\frac{P\; 4}{P\; 1}s_{2}}}} - 1} \right\}}}}} & (2)\end{matrix}$

To determine the unknowns, values for s₂, s, L2, C₀₂ and α₂ may be knownfor each of multiple loads, thus, providing at least a version of thisequation for each unknown. Although equation 2 is shown, otherconversion equations may be used. Equation 2 may be modified and/orreplaced for different variable capacitors, match networks, etc. In oneembodiment, equation 2 is not used.

To simplify the calibration process and/or determination of a conversionmodel, one or more of 416B and 416C may be performed. Operations 416Band 416C may be performed instead of operation 416A. Although theresults of operations 416B and 416C may be less accurate than theresults of operation 416A, the differences may be negligible, as shownbelow.

At 416B, the conversion modules 316, 318, for each variable capacitor,determines coefficients of a polynomial equation, such as a quarticequation, a quadratic equation, or a linear equation. Referencecapacitor positions and corresponding detected variable capacitorpositions are known. If a quartic equation, such as equation 3 is used,coefficients a₀-a₄ are determined, where g(s₂) is a golden matchconversion function used to provide comparable capacitor (or goldenmatch) positions in the method of FIG. 11. At least five pairs ofcapacitor position data are used to provide at least five equations andfive unknowns. As an example, five different data pairs of{s_(2i),s_(i)} with one pair for each of 5 loads of a single plasmaprocessing chamber or one pair for each plasma processing chamberoperating with a same load may be used, where i refers to the number ofthe data pair.

s=g(s ₂)=a ₄ s ₂ ⁴ +a ₃ s ₂ ³ +a ₂ s ₂ ² +a ₁ s ₂ +a ₀  (3)

FIG. 8A shows an example plot of f{s₂} and g(s₂) for detected capacitorpositions s₂. FIG. 8B shows an example plot of error between the curvesof g(s₂) and f{s₂} for the quartic polynomial conversion. As shown, theplot of FIG. 8B is for g(s₂)−f{s₂}. The quartic polynomial closelymatches a curve represented by equation 2. This can be seen by the plotof FIG. 8A. As can be seen the error is negligible. The range of s₂ maybe different than the range of s. As an example, the range of s may be0-650 counts, where the range of s₂ may be 0-1000 counts.

A lower order polynomial equation may be used instead of the quarticpolynomial. The number of pairs of capacitor position data is at leastequal to the order of the polynomial equation. The lower the order ofthe polynomial, the higher the error between f{s₂} and g(s₂). As a firstexample, a quadratic polynomial may be used. Example results are shownin FIGS. 9A and 9B. FIG. 9A shows an example plot of f{s₂} and g(s₂) fordetected capacitor positions, where g(s₂) is represented by a quadraticpolynomial curve. FIG. 9B shows an example plot of error between thecurves of f{s₂} and g(s₂) for the quadratic polynomial conversionexample. As another example, a linear equation may be used. Slope andintercept information corresponding to the linear equation may be storedin the memory 314. Example results are shown in FIGS. 10A and 10B. FIG.10A shows an example plot of f{s₂} and g(s₂), where g(s₂) is representedby a line. FIG. 10B shows an example plot of error between the curves off{s₂} and g(s₂) for the linear conversion example.

At 416C, the conversion modules 316, 318, for each variable capacitor,may plot and/or determine a set of points, wherein each set of pointsrefers to a data pair including one of the reference capacitor positionsand a corresponding one of the actual capacitor positions. As anexample, reference capacitor positions for one or more match networks ofthe same type, one or more loads, and/or one or more plasma processingchambers may be plotted relative to corresponding actual capacitorpositions. As another example, average capacitor positions for differentloads experienced in a same processing chamber and/or the averagecapacitor positions for different loads of different processing chambersmay be plotted relative to the actual capacitor positions. A curvefitting process may then be performed to generate a curve that is curvefit to the set of points. In one embodiment, a least squares fit to apolynomial curve is used. The set of points may be curve fit using apolynomial curve, such as a quartic curve, a quadratic curve, a linearcurve, another polynomial-based curve, and/or a combination thesecurves. For example, a linear curve may be used for a first portion ofpositions and a higher order polynomial curve may be used for a secondportion of the positions. In another embodiment, a lower orderpolynomial equation is used for a limited number of positions. Forexample, a linear curve or a quadratic curve may be used for positionsassociated with 0-650 counts.

The resultant calibrated conversion parameters, mapping relationships,equations, curves, and/or conversion models determined during operation416 may be stored in the memory 314 at 418 and used to convert actualcapacitor positions to comparable capacitor positions during operationof a corresponding plasma processing system. This is further describedwith respect to the method of FIG. 11. The data pairs of s_(2i), s_(i)collected and/or provided during the above-stated method may be storedin the registers 114, 302, where i is an integer greater than or equalto 2. One data pair may be stored for each variable capacitor. In oneembodiment, only the s_(2i) values are stored in the registers 114, 302and later provided to the position conversion controller 54. The methodmay end at 420.

The above-describe method may be periodically repeated to account forshifts over time. This allows for calibrated data to be adjusted andmapping relationships and calibrated conversion models to be updated.

The above-described operations are meant to be illustrative examples;the operations may be performed sequentially, synchronously,simultaneously, continuously, during overlapping time periods or in adifferent order depending upon the application. Also, any of theoperations may not be performed or skipped depending on theimplementation and/or sequence of events.

In FIG. 11, a method of operating the control system 300 and the plasmaprocessing system 10 based on results of the calibration method of FIG.7 is shown. Although the following operations are primarily describedwith respect to the implementations of FIGS. 1-6, the operations may beeasily modified to apply to other implementations of the presentdisclosure. The operations may be iteratively performed.

The method may begin at 500. At 502, the plasma processing system 10 isrun including operating the match networks 17, 32 according to apredetermined recipe. At 504, positions of the variable capacitors ofthe match networks 17, 32 are adjusted to satisfy predeterminedrequirements. The predetermined requirements may include: predeterminedimpedances of the match networks 17, 32, 152 and/or the power splitter153; a predetermined amount of power transfer through the match networks17, 32, 152; a predetermined power ratio between inner and outer coils(e.g., coils 100 and 102 of FIG. 2, coils 166 and 168 of FIG. 3, orcoils L4 and L7 of FIG. 4); and/or other predetermined requirements.

At 506, the position collection modules 310, 312 may collect variablecapacitor position data from the registers 114, 302. This may includecollecting the data pairs s_(2i), s_(i). In an embodiment, the positioncollection modules 310, 312 monitor match networks based on serialnumbers of the match networks and access data pairs stored in theregisters 114, 302 each time digital communication via an interface(e.g., a RS-232 interface, an Ethernet interface, an Ethernet forcontrol automation technology (EtherCat) interface, or other suitableinterface) with the controllers 19, 34 is established. At 508, theconversion modules 316, 318 convert actual detected and/or commandedvariable capacitor positions to comparable capacitor (or golden match)positions. The conversions are performed based on the calibratedconversion parameters, mapping relationships, equations, curves, and/orconversion models determined during operation 416. As an example, anactual capacitor position may be plugged into a conversion equation toprovide the comparable capacitor position. As another example, aconversion plot, curve, table, and/or other mapping relationship may beused to convert the actual capacitor positions.

At 510, the modules 316, 318 store the comparable capacitor positions inthe memory 314 and/or display the comparable capacitor positions fordata logging purposes on the display 50. The comparable capacitorpositions displayed on the display 50 are not actual positions of thecorresponding variable capacitors. By displaying the comparablecapacitor positions, false alarms are prevented. The comparablecapacitor positions should be similar to comparable capacitor positionsof other match networks of the same type regardless of manufacturingdifferences, as a result of the above-described calibration andconversion processes. This prevents a system operator from being alertedof large differences in variable capacitor positions due simply tomanufacturing differences.

In one embodiment, the following operations 512-516 are not performed.At 512, the comparison module 322 may compare the comparable capacitorpositions for two or more match networks of the same type and/or two ormore plasma processing chambers. This data may be collected from thememory 314 of the system controller 46 and/or other memories of othersystem controllers corresponding to any number of plasma processingchambers. This may be done to detect an outlier match network and/orpower splitter that is operating different than other match networksand/or power splitters of the same type and recipe conditions. At 514,the degradation reporting module 324 evaluates results of thecomparisons performed at 512. This may include comparing differences topredetermined values and determining whether the differences exceed thepredetermined values and/or outside predetermined ranges of thepredetermined values. For example, if a difference is greater than orequal to 10 counts (or 1.0% of a full operating range), then an issuemay be reported.

At 516, the degradation reporting module may display detected issueswith the match networks 17, 32, the differences resulting from thecomparisons, values indicating how close the differences are to thepredetermined thresholds and/or predetermined ranges, etc. Thedegradation reporting module may perform a countermeasure when: an issuewith one of the match networks 17, 32 exists; one or more of thedifferences exceeds the corresponding predetermined threshold(s); and/orone or more of the differences is outside the correspondingpredetermined range(s). The countermeasure may include: deactivatingpower and/or limiting power to one or more of the match networks 17, 32;deactivating portions or all of the plasma processing system 10, orother suitable countermeasure. The countermeasure may include performingan action based on an input received from a system operator in responseto the reported information displayed on the display 50. The method mayend at 518.

The above-described operations are meant to be illustrative examples;the operations may be performed sequentially, synchronously,simultaneously, continuously, during overlapping time periods or in adifferent order depending upon the application. Also, any of theoperations may not be performed or skipped depending on theimplementation and/or sequence of events.

In one embodiment, preset values for the variable capacitors of one ormatch networks are provided. The present values may be predeterminedand/or provided via the input device 52 of FIG. 1. The present valuesmay be accessed from the memory 314. The position conversion controller54 performs a reverse conversion from that described above andtranslates s values to s₂ values. Variable capacitor positions are thenadjusted to match the s₂ values, which are the values sent to thecontrollers 19, 34. As an example, a reverse version of equation 2 maybe used for this process.

The above-described methods provide improved mapping of variablecapacitor positions to reference match positions using, for example,polynomial based conversions. The methods provide a range of adjustmentand allow for calibration data to be adjusted to account for shifts overtime.

The foregoing description is merely illustrative in nature and is in noway intended to limit the disclosure, its application, or uses. Thebroad teachings of the disclosure can be implemented in a variety offorms. Therefore, while this disclosure includes particular examples,the true scope of the disclosure should not be so limited since othermodifications will become apparent upon a study of the drawings, thespecification, and the following claims. It should be understood thatone or more steps within a method may be executed in different order (orconcurrently) without altering the principles of the present disclosure.Further, although each of the embodiments is described above as havingcertain features, any one or more of those features described withrespect to any embodiment of the disclosure can be implemented in and/orcombined with features of any of the other embodiments, even if thatcombination is not explicitly described. In other words, the describedembodiments are not mutually exclusive, and permutations of one or moreembodiments with one another remain within the scope of this disclosure.

Spatial and functional relationships between elements (for example,between modules, circuit elements, semiconductor layers, etc.) aredescribed using various terms, including “connected,” “engaged,”“coupled,” “adjacent,” “next to,” “on top of,” “above,” “below,” and“disposed.” Unless explicitly described as being “direct,” when arelationship between first and second elements is described in the abovedisclosure, that relationship can be a direct relationship where noother intervening elements are present between the first and secondelements, but can also be an indirect relationship where one or moreintervening elements are present (either spatially or functionally)between the first and second elements. As used herein, the phrase atleast one of A, B, and C should be construed to mean a logical (A OR BOR C), using a non-exclusive logical OR, and should not be construed tomean “at least one of A, at least one of B, and at least one of C.”

In some implementations, a controller is part of a system, which may bepart of the above-described examples. Such systems can comprisesemiconductor processing equipment, including a processing tool ortools, chamber or chambers, a platform or platforms for processing,and/or specific processing components (a wafer pedestal, a gas flowsystem, etc.). These systems may be integrated with electronics forcontrolling their operation before, during, and after processing of asemiconductor wafer or substrate. The electronics may be referred to asthe “controller,” which may control various components or subparts ofthe system or systems. The controller, depending on the processingrequirements and/or the type of system, may be programmed to control anyof the processes disclosed herein, including the delivery of processinggases, temperature settings (e.g., heating and/or cooling), pressuresettings, vacuum settings, power settings, radio frequency (RF)generator settings, RF matching circuit settings, frequency settings,flow rate settings, fluid delivery settings, positional and operationsettings, wafer transfers into and out of a tool and other transfertools and/or load locks connected to or interfaced with a specificsystem.

In this application, including the definitions below, the term “module”or the term “controller” may be replaced with the term “circuit.” Theterm “module” may refer to, be part of, or include: an ApplicationSpecific Integrated Circuit (ASIC); a digital, analog, or mixedanalog/digital discrete circuit; a digital, analog, or mixedanalog/digital integrated circuit; a combinational logic circuit; afield programmable gate array (FPGA); a processor circuit (shared,dedicated, or group) that executes code; a memory circuit (shared,dedicated, or group) that stores code executed by the processor circuit;other suitable hardware components that provide the describedfunctionality; or a combination of some or all of the above, such as ina system-on-chip.

The module may include one or more interface circuits. In some examples,the interface circuits may include wired or wireless interfaces that areconnected to a local area network (LAN), the Internet, a wide areanetwork (WAN), or combinations thereof. The functionality of any givenmodule of the present disclosure may be distributed among multiplemodules that are connected via interface circuits. For example, multiplemodules may allow load balancing. In a further example, a server (alsoknown as remote, or cloud) module may accomplish some functionality onbehalf of a client module.

The term code, as used above, may include software, firmware, and/ormicrocode, and may refer to programs, routines, functions, classes, datastructures, and/or objects. The term shared processor circuitencompasses a single processor circuit that executes some or all codefrom multiple modules. The term group processor circuit encompasses aprocessor circuit that, in combination with additional processorcircuits, executes some or all code from one or more modules. Referencesto multiple processor circuits encompass multiple processor circuits ondiscrete dies, multiple processor circuits on a single die, multiplecores of a single processor circuit, multiple threads of a singleprocessor circuit, or a combination of the above. The term shared memorycircuit encompasses a single memory circuit that stores some or all codefrom multiple modules. The term group memory circuit encompasses amemory circuit that, in combination with additional memories, storessome or all code from one or more modules.

The term memory circuit is a subset of the term computer-readablemedium. The term computer-readable medium, as used herein, does notencompass transitory electrical or electromagnetic signals propagatingthrough a medium (such as on a carrier wave); the term computer-readablemedium may therefore be considered tangible and non-transitory.Non-limiting examples of a non-transitory, tangible computer-readablemedium are nonvolatile memory circuits (such as a flash memory circuit,an erasable programmable read-only memory circuit, or a mask read-onlymemory circuit), volatile memory circuits (such as a static randomaccess memory circuit or a dynamic random access memory circuit),magnetic storage media (such as an analog or digital magnetic tape or ahard disk drive), and optical storage media (such as a CD, a DVD, or aBlu-ray Disc).

In this application, apparatus elements described as having particularattributes or performing particular operations are specificallyconfigured to have those particular attributes and perform thoseparticular operations. Specifically, a description of an element toperform an action means that the element is configured to perform theaction. The configuration of an element may include programming of theelement, such as by encoding instructions on a non-transitory, tangiblecomputer-readable medium associated with the element.

The apparatuses and methods described in this application may bepartially or fully implemented by a special purpose computer created byconfiguring a general purpose computer to execute one or more particularfunctions embodied in computer programs. The functional blocks,flowchart components, and other elements described above serve assoftware specifications, which can be translated into the computerprograms by the routine work of a skilled technician or programmer.

The computer programs include processor-executable instructions that arestored on at least one non-transitory, tangible computer-readablemedium. The computer programs may also include or rely on stored data.The computer programs may encompass a basic input/output system (BIOS)that interacts with hardware of the special purpose computer, devicedrivers that interact with particular devices of the special purposecomputer, one or more operating systems, user applications, backgroundservices, background applications, etc.

The computer programs may include: (i) descriptive text to be parsed,such as HTML (hypertext markup language), XML (extensible markuplanguage), or JSON (JavaScript Object Notation) (ii) assembly code,(iii) object code generated from source code by a compiler, (iv) sourcecode for execution by an interpreter, (v) source code for compilationand execution by a just-in-time compiler, etc. As examples only, sourcecode may be written using syntax from languages including C, C++, C#,Objective-C, Swift, Haskell, Go, SQL, R, Lisp, Java®, Fortran, Perl,Pascal, Curl, OCaml, Javascript®, HTML5 (Hypertext Markup Language 5threvision), Ada, ASP (Active Server Pages), PHP (PHP: HypertextPreprocessor), Scala, Eiffel, Smalltalk, Erlang, Ruby, Flash®, VisualBasic®, Lua, MATLAB, SIMULINK, and Python®.

Broadly speaking, the controller may be defined as electronics havingvarious integrated circuits, logic, memory, and/or software that receiveinstructions, issue instructions, control operation, enable cleaningoperations, enable endpoint measurements, and the like. The integratedcircuits may include chips in the form of firmware that store programinstructions, digital signal processors (DSPs), chips defined asapplication specific integrated circuits (ASICs), and/or one or moremicroprocessors, or microcontrollers that execute program instructions(e.g., software). Program instructions may be instructions communicatedto the controller in the form of various individual settings (or programfiles), defining operational parameters for carrying out a particularprocess on or for a semiconductor wafer or to a system. The operationalparameters may, in some embodiments, be part of a recipe defined byprocess engineers to accomplish one or more processing steps during thefabrication of one or more layers, materials, metals, oxides, silicon,silicon dioxide, surfaces, circuits, and/or dies of a wafer.

The controller, in some implementations, may be a part of or coupled toa computer that is integrated with the system, coupled to the system,otherwise networked to the system, or a combination thereof. Forexample, the controller may be in the “cloud” or all or a part of a fabhost computer system, which can allow for remote access of the waferprocessing. The computer may enable remote access to the system tomonitor current progress of fabrication operations, examine a history ofpast fabrication operations, examine trends or performance metrics froma plurality of fabrication operations, to change parameters of currentprocessing, to set processing steps to follow a current processing, orto start a new process. In some examples, a remote computer (e.g. aserver) can provide process recipes to a system over a network, whichmay include a local network or the Internet. The remote computer mayinclude a user interface that enables entry or programming of parametersand/or settings, which are then communicated to the system from theremote computer. In some examples, the controller receives instructionsin the form of data, which specify parameters for each of the processingsteps to be performed during one or more operations. It should beunderstood that the parameters may be specific to the type of process tobe performed and the type of tool that the controller is configured tointerface with or control. Thus as described above, the controller maybe distributed, such as by comprising one or more discrete controllersthat are networked together and working towards a common purpose, suchas the processes and controls described herein. An example of adistributed controller for such purposes would be one or more integratedcircuits on a chamber in communication with one or more integratedcircuits located remotely (such as at the platform level or as part of aremote computer) that combine to control a process on the chamber.

Without limitation, example systems may include a plasma etch chamber ormodule, a deposition chamber or module, a spin-rinse chamber or module,a metal plating chamber or module, a clean chamber or module, a beveledge etch chamber or module, a physical vapor deposition (PVD) chamberor module, a chemical vapor deposition (CVD) chamber or module, anatomic layer deposition (ALD) chamber or module, an atomic layer etch(ALE) chamber or module, an ion implantation chamber or module, a trackchamber or module, and any other semiconductor processing systems thatmay be associated or used in the fabrication and/or manufacturing ofsemiconductor wafers.

As noted above, depending on the process step or steps to be performedby the tool, the controller might communicate with one or more of othertool circuits or modules, other tool components, cluster tools, othertool interfaces, adjacent tools, neighboring tools, tools locatedthroughout a factory, a main computer, another controller, or tools usedin material transport that bring containers of wafers to and from toollocations and/or load ports in a semiconductor manufacturing factory.

What is claimed is:
 1. A control system comprising: a memory configuredto store position data of first positions of a first variable capacitorof a first match network of a first plasma processing system, andwherein each of the first positions of the first variable capacitorcorresponds to a respective one of a plurality of loads experienced bythe first match network; and a conversion module configured to obtainthe position data stored in the memory, determine reference capacitorpositions based on the position data, determine a calibrated conversionmodel based on the reference capacitor positions, wherein the calibratedconversion model converts second positions of the first variablecapacitor to comparable capacitor positions, and wherein the secondpositions are positions of the first variable capacitor existingsubsequent to the determination of the calibrated conversion model, andstore the calibrated conversion model.
 2. The control system of claim 1,further comprising: a match network controller of the first matchnetwork, wherein the match network controller comprises a register, andwherein the register is configured to store the position data; and aposition collection module separate from the match network controllerand configured to (i) obtain the position data stored in the register ofthe match network controller, and (ii) store the position data in thememory.
 3. The control system of claim 1, wherein the comparablecapacitor positions are comparable to third positions of a secondvariable capacitor of a second match network, such that effects ofmanufacturing differences between the first match network and the secondmatch network on differences between the second positions and the thirdpositions are minimized.
 4. The system of claim 3, wherein: thecomparable capacitor positions are comparable to the third positions ofthe second match network, such that effects of manufacturing differencesbetween the first plasma processing system and a second plasmaprocessing system on differences between the second positions and thethird positions are minimized; the second match network is a same typeof match network as the first match network; and the second matchnetwork is operated for the second plasma processing system.
 5. Thesystem of claim 3, wherein the third positions are comparable capacitorpositions determining using a second calibrated conversion model.
 6. Thesystem of claim 1, wherein the calibrated conversion model includesconversion parameters, a mapping relationship, and a conversionequation.
 7. The system of claim 6, wherein the conversion equation is apolynomial equation.
 8. The system of claim 6, wherein the conversionequation is a quartic polynomial equation.
 9. The system of claim 1,further comprising a position collection module configured to (i) obtainthe position data from a register of a match network controller, (ii)store the position data in the memory, and (iii) collect position datafrom the register of a second match network controller of a second matchnetwork, wherein the conversion controller is configured to determinethe reference capacitor positions based on the position data receivedfrom the register of the second match network controller.
 10. The systemof claim 1, a position collection module configured to collect positiondata from registers of a plurality of controllers controlling operationof a plurality of match networks, wherein the plurality of matchnetworks include the first match network and correspond to at least oneplasma processing chamber; and the conversion module is configured todetermine the reference capacitor positions based on the position datareceived from the registers of the plurality of controllers.
 11. Thesystem of claim 1, wherein the reference capacitor positions are resultsof the conversion module adjusting the second positions to satisfypredetermined operating requirements of the first plasma processingsystem to generate the calibrated conversion model.
 12. The system ofclaim 1, further comprising a match network controller of the firstmatch network, wherein the match network controller comprises aregister, wherein: the register is configured to store the positiondata; the match network controller is configured to control adjustmentof a position of the first variable capacitor while the first plasmaprocessing system is operating according to a first recipe and while thefirst match network is providing power to a first load; the matchnetwork controller is configured to, prior to the conversion moduleaccessing the position data from the register of the match networkcontroller, adjust the position of the first variable capacitor tosatisfy at least one predetermined requirement; and the predeterminedrequirement includes at least one of (i) a predetermined impedance ofthe first match network, (ii) a predetermined amount of powertransferred through the first match network, or (iii) a predeterminedpower ratio between an inner coil and an outer coil of a transformercoupled capacitive tuning network.
 13. A control system comprising: amemory configured to store position data of first positions of avariable capacitor of a first power splitter of a first plasmaprocessing system, and wherein each of the first positions of thevariable capacitor corresponds to a respective one of a plurality ofloads experienced by the first power splitter; and a conversion moduleconfigured to obtain the position data stored in the memory, determinereference capacitor positions based on the position data, determine acalibrated conversion model based on the reference capacitor positions,wherein the calibrated conversion model converts second positions of thevariable capacitor to comparable capacitor positions, and wherein thesecond positions are positions of the variable capacitor existingsubsequent to the determination of the calibrated conversion model, andstore the calibrated conversion model.
 14. The control system of claim13, wherein the comparable capacitor positions are comparable to thirdpositions of a variable capacitor of a second power splitter, such thateffects of manufacturing differences between the first power splitterand the second power splitter on differences between the secondpositions and the third positions are minimized.
 15. The system of claim13, wherein: the calibrated conversion model includes conversionparameters, a mapping relationship, and a conversion equation; and theconversion equation is a quark polynomial equation.
 16. A systemcomprising: a first controller configured to control operation of aplasma processing system; and a memory configured to store position dataof a first variable capacitor of a first match network of the plasmaprocessing system, wherein the first controller comprises a conversionmodule configured to (i) obtain the position data of the first variablecapacitor stored in the memory, wherein the position data includes firstpositions of the first variable capacitor for a respective plurality ofloads on the first match network, and (ii) convert the first positionsto comparable capacitor positions based on a calibrated conversionmodel, wherein the calibrated conversion model is based on referencecapacitor positions of the first variable capacitor, and a displaymodule configured to display the comparable capacitor positions on adisplay.
 17. The system of claim 16, further comprising a secondcontroller configured to: control adjustment of a position of the firstvariable capacitor while the plasma processing system is operatingaccording to a first recipe and while the first match network isproviding power to a first load; adjust the position of the firstvariable capacitor to satisfy at least one predetermined requirement;and store a resultant position of the first variable capacitor in aregister when the at least one predetermined requirement is satisfied,wherein the plurality of loads include the first load, and the firstcontroller is configured to access the register to obtain the resultantposition of the first variable capacitor, and the first positionsinclude the resultant position.
 18. The system of claim 17, wherein: thefirst recipe is different than a second recipe; and the second recipe isused during calibration to generate the calibrated conversion model. 19.The system of claim 17, wherein the predetermined requirement includesat least one of (i) a predetermined impedance of the first matchnetwork, (ii) a predetermined amount of power transferred through thefirst match network, or (iii) a predetermined power ratio between aninner coil and an outer coil of a transformer coupled capacitive tuningnetwork.
 20. The system of claim 16, wherein the calibrated conversionmodel includes conversion parameters, a mapping relationship, and aconversion equation.
 21. The system of claim 20, wherein the conversionequation is a polynomial equation.
 22. The system of claim 20, whereinthe conversion equation is a quartic polynomial equation.
 23. The systemof claim 16, further comprising: a comparison module configured tocompare the first positions to second positions, wherein the secondpositions are positions of a second variable capacitor of a second matchnetwork, wherein the second match network is a same type of matchnetwork as the first match network; and a degradation reporting moduleconfigured to (i) evaluate results of the comparisons, and (ii) based onthe results, indicate whether an issue exists with the first matchnetwork.